This book is an overview of the career of the FBI man who nearly single-handedly created the system for personality profiling of violent offenders. If there's a big-time multiple murderer from about 1950 until now who hasn't been interviewed by Robert Ressler, he probably refused the honor. Indispensable reading for serial killer mavens, and better written than John Douglas and Mark Olshaker's Mindhunter, this book is packed with fascinating details from dozens of cases: The killer John Joubert, for example, started his life of cruelty as a kid one day when he was riding his bike with a sharpened pencil in his hand. He rode up next to a little girl who was walking, and stabbed her in the back with the pencil. Ouch!